[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

Roman Kononov kononov195-lbl at yahoo.com
Thu Feb 1 20:49:29 CET 2007

I have Sun Ultra40 workstation. Southbridge is nVidia CrushK8-04/nforce
2200 (too many names, sounds like a criminal).

1) Linuxbios loads kernel A; kernel A loads kernel B. Everything works fine.

2) Then I push the reset button.

3) Linuxbios loads kernel A; kernel A loads kernel B. Kernel B complains
about wrong checksum of the mptable and crushes later.

An investigation showed that in 3), short after kernel A (v2.6.19.2) sets
the Bus Master Enable bit of the nVidia's USB1 controller (pci_set_master()),
the mptable gets two bytes at physical address 0x80 damaged.

Nothing is plugged to the USB ports. Other two Sun workstations had the same
behavior. This does not make sense to me unless the controller has a HW bug.

I believe, this should better be fixed in the kernel USB driver.

For now this patch offers a possibility for linuxbios to reset the USB
controller by setting HostControllerReset bit in HcCommandStatus Register.
It is enablead by using 'register "usb1_hc_reset"="1"' in 'chip
southbridge/nvidia/ck804' section of the mainboard's Config.lb.

Signed-off-by: Roman Kononov <kononov195-lbl at yahoo.com>

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